1. Field of the Invention
The present invention relates to electrical switches and controllers and more particularly to a touch actuated switching system that provides delayed response timing for termination of electrical power to a controlled device. The invention further relates to a touch control system allowing selection between a plurality of alternate ON states, an OFF state, and a delayed OFF state for an illumination device.
2. Background of the Art
Touch control switching systems, especially for controlling illumination devices, have proven appealing due to their added convenience and aesthetics. However, incorporation of multiple power level dimming schemes in such systems or switches has typically required use of complex touch or contact sequences which have proven annoying or to difficult to remember and use for noncommercial applications.
To decrease the operational complexity by decreasing the number of discrete contact elements that must be separately touched during operation, a class of switches based on membrane contacts were developed. In membrane switching a series of switch contact is are manufactured on the surfaces of one or more adjacent membranes which are deformed into contact by touch. This allows a series of contact elements or patterns to be built into a relatively compact structure which is operated by touching an exterior surface which generally hides the underlying contact structure. A variety of otherwise complex power or lighting level control schemes are accommodated through a specific, and complex, interconnection of contacts without requiring knowledge by the switching system user. The user only needs to follow a simple contact pattern on an exterior surface which is interpreted by the more complex underlying pattern of switch contacts.
However, present membrane switching techniques have a number of drawbacks which seriously limit their suitability for many applications. One drawback is a requirement for relatively high actuation forces which reduces their aesthetic appeal and their utility for users having limited hand or finger mobility or strength. A second drawback is the generally complex multi-layered construction techniques for present membrane switches which adds to their cost and complexity.
At the same time, an inadequacy of all prior techniques for switching lights is that switching systems automatically turn lights completely off before a system user can leave the room or building. Thus, the user must fumble in the dark to leave the previously illuminated area or leave a light on.
What is needed is a method and apparatus for proving touch actuated control over the brightness or light output of lamps or similar illumination devices that is easy to use and provides a more convenient output scenario when adjusting to an off state.